The present invention particularly refers to compactly designed cutting inserts for mounting thereof on a cutting tool where the space available for arranging insert receiving pockets therein is limited. This specifically concerns rotary cutting tools of the type used in end milling, drilling and plunging operations and the like, which are formed with a plurality of chip evacuation flutes and which bear cutting inserts on a front face thereof between the flutes.
In order to make efficient use of the space available for mounting the cutting inserts at the front face surface of such cutting tools, it is desirable to optimize the geometry of the cutting inserts so as to enable them to have relatively long cutting edges with trailing mounting portions being of substantially reduced dimensions.
Patent Application No. PCT/IL97/00270 discloses a cutting insert designed to solve the above problem in an end-milling cutter. The cutting insert comprises a front cutting portion having an operative front surface associated with upper and lower arcuate cutting edges and side edges therebetween, and a trailing mounting portion having upper, lower and side walls, all extending away from the respective edges of the front cutting portion, the side walls converging in the direction away from the front cutting portion, and being shorter than a distance between extreme points of each arcuate cutting edge. The insert is formed with a clamping screw bore passing through the upper and lower walls of the trailing mounting portion, and is mounted on the cutter so that an axis of this bore is substantially perpendicular to the rotary axis of the cutter.
U.S. Pat. No. 4,768,901 discloses a cutting insert mounted on a front face of a drilling tool. The cutting insert has a front cutting portion associated with a cutting edge and a trailing mounting portion having upper, lower and side walls, and a rear wall extending therebetween. The cutting insert has a clamping screw bore which passes through the upper and lower walls of the trailing mounting portion, the insert being mounted so that an axis of the clamping screw bore is parallel to a rotary axis of the drilling tool. The rear wall of the trailing mounting portion comprises stepped lateral abutment surfaces disposed adjacent the side walls of the trailing mounting portion relatively close to the cutting edge, and semi-cylindrical central surface disposed between the lateral abutment surfaces and extending around a rear portion of the clamping screw bore.
It is the object of the present invention to provide a new cutting insert which, inter alia, has advantages in respect of its mounting in a cutting tool of the above kind.